In a four-quart saucepan, bring three quarts of liberally salted water to a boil over high heat. When the water boils, reduce heat to simmer until you’re ready to cook the pasta.
While the water is heating up, grate the skin of the lemon into a small saucepan. Cut the lemon in half and squeeze 1 tablespoon of the juice into the pan, removing any seeds. Reserve the other 1 tablespoon of lemon juice for step 5. Add the garlic and one tablespoon of olive oil to the saucepan. Stir to blend well. Place on stovetop on low heat.
Heat a large nonstick pan with 2 tablespoons of olive oil over high heat until very hot and almost smoking. Season the scallops with salt and pepper.
Place the scallops in the hot pan seasoned side down in a clockwise fashion beginning at 12 o'clock. Sear for 1 minute until golden at the edges, then turn them in the same order that you placed them in the pan, and cook the other side for no longer than another 1 minute on the second side. The perfectly seared scallop is seared yet still soft, white and glistening with juices in the center.
When both sides of the scallop are nicely golden brown in color, add the lemon juice to pan, making sure to coat the scallops with the lemon juice.
Meanwhile, after turning the scallops to the second side, drop the pasta into the boiling water and cook according to package directions.
Drain the pasta reserving 1/2 cup of pasta water. Return the drained pasta to the pot, and toss with the warm lemon-olive oil mixture and the reserved pasta water - to keep it from sticking.
Divide the pasta equally among four plates (about one cup per plate). Top each plate with four scallops.
Garnish each dish with shredded Parmesan cheese and freshly chopped parsley. Serve immediately. [See Note 2]
Sea scallops are larger scallops and Bay scallops are the tiny ones. I prefer sea scallops over Bay scallops but you can certainly use Bay scallops if that's what you prefer. The cooking times will be much different due to the size of the Bay scallops.
Scallops are not the best reheated. They are best enjoyed freshly cooked.